KR102489193B1 - Silicone-titanium dioxide composite powder for UV-screening and the method for preparing the same - Google Patents

Abstract

The present invention relates to a composite powder composed of titanium dioxide powder and silicon, which is an inorganic sunscreen agent included in a sunscreen composition, and a method for preparing the same, wherein the core-shell composite powder of the present invention has excellent sunscreen performance (SPF 50+ , PA ++++), but the particle diameter of the powder reaches several microns, so controversy over the harmfulness of nanoparticles to the human body can be avoided, and the manufacturing process is simplified and cost-effective manufacturing is possible. It's about manufacturing methods.

Description

Silicon-titanium dioxide composite powder for UV-screening and the method for preparing the same}

The present invention relates to a composite powder composed of titanium dioxide powder and spherical silicon powder, which is an inorganic sunscreen agent included in a sunscreen composition, and a method for preparing the same, which is nano-sized dioxide used to minimize whitening when applied to the skin. It relates to a multi-micron-sized composite powder that forms a coating layer on micron-sized spherical silicon and exhibits excellent UV blocking performance without controversy about harmfulness to the human body and a manufacturing method thereof.

In order to prevent skin damage and aging due to exposure to ultraviolet rays, sunscreens are widely used. Among the sunscreens, there are organic sunscreens and inorganic sunscreens, and inorganic sunscreens, which are metal oxide powders such as ZnO and TiO ₂ , are preferred due to their efficacy and stability.

In the case of inorganic sunscreens, powders of nano size (generally, less than 40 nm) are preferred in order to reduce the whitening phenomenon that occurs when applied to the skin. Since the particles are large, there is a disadvantage in that a pre-dispersed slurry must be used, and it is not easy to mix uniformly. In addition, conventional nano-sized TiO ₂ The powder has been shown to have a strong UV blocking ability for the UV B region, but a relatively weak UV blocking ability for the UV A region, and controversy over harmfulness to the human body continues due to the nano-level particle size.

Nano TiO ₂ as such a sunscreen In order to improve the problem of powder and impart hydrophobicity, nano TiO ₂ The surface of the powder is coated with alumina and/or silica, and further coated with alkylsilane, silicon oil such as dimethicone, stearic acid, or the like, to provide hydrophobicity and fluidity, and the powder is commercially available. These powders facilitate the preparation of uniform lotions or creams.

However, the problem of skin penetration of nano-sized powder has been steadily raised, and as a solution to this problem, non-nano TiO ₂ is commercially available.

JP 2012-229168A discloses a composite powder by dry mixing organic spherical powder (PMMA, D ₅₀ = 8 μm) and nano titanium dioxide powder at high speed.

Korean Registered Patent No. 10-20140008 (Waker Haemi AG, 2020) discloses silica-coated silicone rubber particles by making and curing a silicone emulsion in a silica aqueous dispersion. The amount of silica is 3 to 5% by weight, for maintaining the silicone rubber particles in a spherical shape and imparting smooth fluidity.

In addition, Korean Registered Patent No. 10-1138235 (Sunjin Chemical, 2012) is a method of liquid phase precipitation of tetraethoxysilane on the surface of titanium dioxide from alkali, which is obtained by removing fine powder of 100 nm or less after multi-layer surface treatment with silica. The powder is dried by heat treatment at 105° C., and then a hydrophobic treated micron-sized titanium dioxide powder is disclosed.

However, the titanium dioxide powder of the prior art has inconveniences in that the powder is hard and the feeling of use is poor, and that it needs to go through several coating and separation processes, and that a hydrophobic treatment process must be separately performed after coating.

An object of the present invention is to coat the surface of several micron-sized silicone elastomer beads with nano-sized titanium dioxide powder, thereby avoiding the controversy over skin permeability of nano-powder, having a wide range of UV protection, and a composite powder that can be usefully applied to cosmetics, and It is to provide a manufacturing method thereof.

In order to achieve the above object, the present invention is a core made of spherical silicone elastomer beads; and a shell composed of nano-sized titanium dioxide particles and an additive, wherein the additive is at least one selected from the group consisting of a dispersing agent, a coupling agent, and an organic-inorganic composite sol binder, a silicon-titanium dioxide composite for UV protection. powder is provided.

In addition, the present invention

(1) preparing a titanium dioxide slurry by dispersing nano-sized titanium dioxide powder in alcohol in an amount of 10 to 40% by weight based on the total weight of the slurry;

(2) preparing silicone elastomer beads as a silicone aqueous dispersion of 5 to 30% by weight based on the total weight of the dispersion;

(3) mixing the slurry of (1) and the dispersion of (2) to form a precipitate;

(4) separating the precipitate of (3) and drying it at high temperature to produce a composite powder; and

(5) pulverizing the composite powder of (4) by dry milling to prepare micron-sized powder;

Including,

Mixing additives in at least one of step (1), step (2), or step (3),

The additive is at least one selected from the group consisting of a dispersing agent, a binder, and an organic-inorganic composite sol binder, and provides a method for preparing a silicon-titanium dioxide composite powder for UV protection.

The silicon-titanium dioxide composite powder according to an embodiment of the present invention is a spherical powder of several microns, free from controversy over the possibility of particles penetrating into the skin, and exhibits high SPF and PA values, thereby having a very excellent sunscreen effect. In addition, silicone elastomer used as a component of the core is soft to the touch and is a cosmetic that is usefully used in cosmetics. By using commercially available hydrophobic nano-titanium dioxide powder as a sunscreen, after coating the titanium dioxide nano-powder, there is no need for a hydrophobic treatment process, which is generally performed with silica or alumina precursors and alkylsilane, dimethicone, stearic acid, etc. Therefore, no washing process is required. In addition, compared to the conventional nano-titanium dioxide composite powder for UV-blocking, there is an advantage in that an excellent UV-blocking effect can be provided even with the amount of nano-titanium dioxide used at a level of 60 to 70%.

1 is a scanning electron microscope (SEM) observation photograph of silicone elastomer bead powder used in Examples and Comparative Examples.
2 is a scanning electron microscope (SEM) observation photograph of a composite powder coated with nano-titanium dioxide powder on the surface of a silicone elastomer bead of Example 1 prepared according to the present invention.
3 is a scanning electron microscope (SEM) observation photograph of a composite powder coated with nano-titanium dioxide powder on the surface of a silicone elastomer bead of Example 3 prepared according to the present invention.
4 is a scanning electron microscope (SEM) observation photograph of a composite powder coated with nano-titanium dioxide powder on the surface of a silicone elastomer bead of Example 4 prepared according to the present invention.
5 is a scanning electron microscope (SEM) observation photograph of a composite powder coated with nano-titanium dioxide powder on the surface of a silicone elastomer bead of Example 5 prepared according to the present invention.
6 is a scanning electron microscope (SEM) observation photograph of a composite powder coated with nano-titanium dioxide powder on the surface of a silicone elastomer bead of Comparative Example 1 prepared according to the present invention.
7 is a scanning electron microscope (SEM) observation picture of a composite powder coated with nano-titanium dioxide powder on the surface of a silicone elastomer bead of Comparative Example 2 prepared according to the present invention.

The present invention relates to a composite powder composed of nano-titanium dioxide powder and silicon that exhibits excellent blocking power in all areas of UVA and UVB while avoiding the possibility of skin penetration and is easy to manufacture, and a manufacturing method thereof.

The composite powder according to an embodiment of the present invention is a composite powder having a core-shell structure, wherein the core portion includes spherical silicon elastomer beads and the shell portion includes nano-sized titanium dioxide particles, At least one of a dispersing agent, a binder, and an organic-inorganic complex sol binder.

In one embodiment of the present invention, the silicone elastomer beads of the core part are silicone rubber, which is synthesized by polymerization of vinyl silicone and hydrogen silicone. In general, silicone elastomer beads are spherical powders with smooth surfaces, and are characterized by severe aggregation between powders during drying.

In one embodiment of the present invention, the titanium dioxide particles of the shell portion may be titanium dioxide of a size commonly used in the art for blocking ultraviolet rays, and to reduce whitening, the size of a single particle is preferably 15 to 100 nm, preferably 15 nm or more and less than 40 nm.

In one embodiment of the present invention, the composite powder includes an additive in the shell portion for surface modification of the nano-titanium dioxide. In one embodiment of the present invention, the additive is at least one selected from the group consisting of a dispersant, a binder, and an organic-inorganic composite sol binder.

In one embodiment of the present invention, a dispersing agent or binder is used to modify the surface of the silicone elastomer and to uniformly form and adhere the titanium dioxide coating layer to the surface of the silicone elastomer bead.

In one embodiment of the present invention, citric acid, malic acid, maleic acid, fumaric acid, succinic acid, acetic acid, formic acid, butanoic acid, hydrochloric acid, nitric acid, and the like can be used as the dispersant, as non-limiting examples.

In one embodiment of the present invention, the dispersant is included in an amount of 0.3 to 3% by weight based on the weight of titanium dioxide. If the content is less than 0.3% by weight, the dispersing effect is not great, and if it is more than 3% by weight, it is used excessively.

In one embodiment of the present invention, the binder is an aminoalkyl silane-based material, including but not limited to 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-(2-aminoethylamino) Propyltriethoxysilane etc. can be used.

In one embodiment of the present invention, the binder is included in an amount of 0.05 to 2% by weight based on the weight of the silicon beads. If the content is less than 0.05% by weight, the bonding effect is not great, and if it is more than 2% by weight, it is used excessively.

In one embodiment of the present invention, the organic-inorganic composite sol binder is a sol synthesized by reacting peptided boehmite with epoxy silane. Specifically, (a) after dispersing boehmite powder in distilled water, acid is added heating and stirring to form an alumina sol; and (b) mixing and heating the formed alumina sol and epoxysilane.

In one embodiment of the present invention, acids used in the preparation of the organic-inorganic composite sol binder include, but are not limited to, acetic acid, formic acid, propionic acid, Nitric acid, hydrochloric acid, etc. are included.

In one embodiment of the present invention, the organic-inorganic composite sol binder is included in an amount of 2 to 15% by weight based on the weight of titanium dioxide. If the content is less than 2% by weight, the amount of the binder is small and there is titanium dioxide powder that does not stick, and if it exceeds 15% by weight, the binder layer becomes thick and the UV blocking performance may be deteriorated.

In one embodiment of the present invention, the content of titanium dioxide in the composite powder is 40 to 80% by weight based on the total weight of the composite powder.

In one embodiment of the present invention, the silicon-titanium dioxide composite powder can be prepared by a method comprising the following steps:

(1) preparing a titanium dioxide slurry by dispersing nano-sized titanium dioxide powder in alcohol in an amount of 10 to 40% by weight based on the total weight of the slurry;

(2) 5 to 30 silicone elastomer beads based on the total weight of the dispersion preparing a silicone aqueous dispersion in weight percent;

(3) mixing the slurry of (1) and the dispersion of (2) to form a precipitate;

(4) separating the precipitate of (3) and drying it at high temperature to produce a composite powder; and

(5) pulverizing the composite powder of (4) by dry milling to prepare micron-sized powder;

includes

In one embodiment of the present invention, additives may be mixed in at least one of step (1), step (2), or step (3).

In one embodiment of the present invention, the additive is at least one selected from the group consisting of a dispersing agent, a binder, and an organic-inorganic composite sol binder.

Preferably, in one embodiment of the present invention, at least one of a dispersing agent and a binder may be added in step (1) or step (2), and an organic-inorganic composite sol binder may be added in step (3). there is.

In one embodiment of the present invention, the composite powder prepared by the above method is a composite powder for UV protection.

In one embodiment of the method of the present invention, the alcohol used in step (1) is at least one selected from the group consisting of ethanol, isopropanol and butanol.

In one embodiment of the present invention, the mixing in step (3) is performed at a weight ratio of alcohol and water as a solvent of 1:1 to 1:4, preferably 1:2.

In one embodiment of the method of the present invention, drying in step (4) is carried out at a temperature of 90 ° C to 120 ° C.

Since the method according to the present invention is to coat the silicone elastomer powder with commercially available hydrophobic nano-titanium dioxide powder, there is no need to go through a separate hydrophobic treatment process. In addition, it is possible to avoid the generation of chemicals such as ammonia generated in the hydrophobic treatment process, and there is no need to go through a washing process for removing these chemicals. Therefore, it has the advantage that the composite powder can be used immediately after filtering and drying, and the manufacturing process of the composite powder for use as a cosmetic component is simplified compared to conventional composite powders and is economical in time and cost.

Since the composite powder prepared according to an embodiment of the present invention is coated with titanium dioxide powder on several micron-sized silicon elastomer beads, there is no problem with harm to the human body due to the use of nano-sized powder, and not only in the ultraviolet B region, It shows excellent UV blocking effect even in the UV A area. In addition, the use of silicone elastomer beads can show a soft feeling, and the surface of highly agglomerated silicon particles is coated with nano-titanium dioxide to become free-flowing powder, which can be usefully applied to cosmetics.

In addition, compared to the existing nano-titanium dioxide powder with severe aggregation, the composite powder according to an embodiment of the present invention exists apart from the particles, and titanium dioxide exists outside the powder, so that even with the use of a smaller amount of the composite powder than before It can exhibit equal or superior sunscreen effect.

In one embodiment of the present invention, the silicon-titanium dioxide composite powder can be used in a sunscreen composition, specifically, a sunscreen cosmetic. In addition, the dosage form may also be appropriately applied in a liquid type, cream type, cake type, and the like.

In one embodiment of the present invention, the composite powder is 5 to 20% by weight, preferably 5 to 20% by weight, based on the total weight of the composition, in consideration of sunscreen effect, skin irritation, miscibility with other sunscreen ingredients, formulation stability, etc. Preferably it is included in an amount of 8 to 15%.

Hereinafter, the contents of the present invention will be described in more detail with examples and test examples. However, these examples and test examples are provided only for illustrative purposes to aid understanding of the present invention, and the scope and scope of the present invention are not limited by the following examples.

[Preparation Example 1] Preparation of organic-inorganic composite sol (G sol) binder

The organic-inorganic composite sol was synthesized by reacting peptized boehmite with epoxy silane, and was prepared as follows.

30 g of boehmite powder was added to 260 ml of distilled water with stirring to prepare a slurry, then 3.3 g of acetic acid was added and stirred at room temperature for 1 hour. Then, it was heated to 70° C. and reacted for 2 hours, cooled to room temperature, and distilled water was added so that the total weight was 300 g to synthesize a 10% by weight alumina sol. After adding 39 g of 5% by weight acetic acid solution to 130 g of 3-glycidoxypropyltrimethoxysilane (GPS) and stirring at room temperature for 1 hour, 377.2 g of the prepared alumina sol was added while heating to 70 ° C. , and reacted with heating for 4 hours to prepare 25% by weight of G sol. This composite sol formed a transparent film when dried at 100 ° C., and the formed film was insoluble in water and ethanol and could be used as a binder.

[Examples and Comparative Examples] Preparation of silicon-titanium dioxide composite powder

<Example 1>

A slurry was prepared by dispersing 80 g of lipophilic surface-treated titanium dioxide powder (MT-100SJ, particle diameter of about 20 nm, Sunjin Beauty Science) in 200 g of ethanol in a 500 ml beaker, and heated to about 60 ° C as a dispersing agent. 4.82 g of citric acid (10% by weight aqueous solution of citric acid) was added, followed by stirring for 2 hours. Next, 17.67 g of G sol (organic-inorganic composite sol, 25 wt%) of Preparation Example 1 was added as a binder, and stirring was continued for 1 hour to prepare a surface-treated TiO ₂ slurry (A).

In a separate beaker, an aqueous dispersion (B) was prepared by dispersing 42.17 g of silicone elastomer beads (SB 902, 70% by weight dispersion, Kyunglim Co., Ltd.; hereinafter referred to as 'SBD') in 200 g of distilled water.

Then, 50 g of ethanol and 5 g of distilled water were put in a 1000 ml beaker, heated to about 60° C. while stirring, and the slurry (A) and the dispersion (B) were slowly and simultaneously added to co-precipitate. After co-precipitation was completed, the mixture was further heated for 1 hour and then cooled to room temperature. After the upper water is clear and the sediment layer is formed, the upper water is poured out, filtered using filter paper (#1 Whatman, 11 ㎛), separated without washing, dried at 60 ° C, then dried at 105 ° C, dry ball milling It was pulverized by dry ball milling and passed through a 200 mesh sieve to prepare a composite powder.

<Example 2>

In Example 1, the same as in Example 1, except that the amount of citric acid (10% by weight aqueous solution of citric acid) added was 3.2 g and the amount of binder G sol (25% by weight) was 16.32 g. A silicon-titanium dioxide composite powder was prepared by the method.

<Example 3>

A slurry prepared by putting 40.0 g MT-100SJ, 160 g ethanol and 4.8 g citric acid solution (5% by weight) in a beaker and stirring for 2 hours, and a dispersion obtained by adding 36.0 g SBD (70% by weight) to 200 g of distilled water and stirring vigorously After co-precipitation by the method described in Example 1, stirring for another 3 hours, adding 200 g of distilled water and stirring for another 30 minutes, stopping stirring and allowing the precipitate to settle. After adding 8.0 g of G sol (25% by weight) and stirring for 2 hours, the precipitate was separated and heat treated in the same manner as described in Example 1 to prepare a silicon-titanium dioxide composite powder.

<Example 4>

A silicon-titanium dioxide composite powder was prepared in the same manner as in Example 3, except that citric acid was not used.

<Example 5>

In Example 3, except that no binder was used and citric acid was not added to the titanium dioxide slurry, citric acid was used in an amount of 0.2% by weight (1.0 g; 5% by weight citric acid aqueous solution) in the SBD dispersion with respect to SB Then, co-precipitation, precipitation separation, and heat treatment were performed in the same manner as described in Example 3 to prepare a silicon-titanium dioxide composite powder.

<Comparative Example 1>

Silicon-titanium dioxide was prepared in the same manner as in Example 1, except that only titanium dioxide powder (MT-100SJ) and silicon elastomer bead dispersion (SBD) were used so that the titanium dioxide content was 81% by weight without using any additives. A composite powder was prepared.

<Comparative Example 2>

Except for the case where only the titanium dioxide slurry containing the dispersion of SBD (70 wt%, average particle size = 3.5 μm) and 0.6 wt% of citric acid was used without a binder and the titanium dioxide content was 37.7 wt%, the above example was prepared. A silicon-titanium dioxide composite powder was prepared in the same manner as in 1.

<Example 6>

After putting 250 g of ethanol in a 500 ml beaker and adding 100.25 g of MT-100TV (Tayca, particle diameter of about 15 nm), stirring for about 1 hour while heating at about 60 ° C, 8.5 g of citric acid aqueous solution (10% by weight) ) was added and stirred for an additional 2 hours to prepare a titanium dioxide slurry (A').

Put 95.8 g SBD (SB 902, 70 wt%) in a 1000 ml beaker, add 650 g of distilled water, stir to disperse, and then add 0.79 g A1120 (50 wt% in ethanol, 3-aminopropyltriethoxysilane) After stirring for 2 hours, an SB dispersion (B') was prepared.

100 g of distilled water and 10 g of ethanol were put in a 2000 ml beaker, heated to 60° C., and the titanium dioxide slurry (A′) and the SB dispersion (B′) were simultaneously added to co-precipitate with stirring, followed by further heating for 2 hours, After stirring, the heating was turned off, and after cooling to room temperature while stirring, stirring was stopped and the precipitate settled. After the precipitate settled, the clear upper water was discarded, and 14.6 g of G sol (25% by weight) of Preparation Example 1 was added as a binder, stirred for 2 hours, filtered, and separated. This powder was dried at 60°C and then at 105°C to obtain a hydrophobic composite powder.

<Example 7>

In Example 6, A1120 was not added, the amount of citric acid was 6 g, and the amount of binder G sol (25% by weight) was 20 g, but in the same manner as in Example 6, silicon - A titanium dioxide composite powder was prepared.

[Test Example 1] Powder surface observation by SEM

The silicone elastomer bead powder used in the above Examples and Comparative Examples (FIG. 1) and the surface of the silicone elastomer beads prepared in Examples (Examples 1, 3, 4, and 5) and Comparative Examples (Comparative Examples 1 and 2) were nano The composite powder coated with the titanium dioxide powder was observed with a scanning electron microscope (SEM), and these are shown in FIGS. 2 to 7, respectively.

As shown in FIG. 1, the silicone elastomer beads (SB) are spherical powders with smooth surfaces, and exhibit uneven particle sizes and severe aggregation. 2 to 5 are composite powders coated with nano-titanium dioxide powder of an embodiment prepared according to the present invention, the surface is evenly coated with titanium dioxide powder so that the smooth surface of the silicone elastomer beads is not visible, and the aggregation of the silicone elastomer beads is high You can see it fell.

Figure 6 shows that the composite powder prepared without using the additives of Comparative Example 1 shows that the nano-powder is not used in the silicon coating and remains in large quantities, as expected. 7 is a composite powder prepared with a titanium dioxide content of 37.7% by weight, and the surface is well coated without aggregation of the silicon elastomer beads, but the titanium dioxide content is insufficient, so that the area where the silicon elastomer beads are agglomerated is slightly show the existence

In Examples 1, 3, and 4 using a binder, it can be seen that the surface of the particles is more distinct and uniform compared to Example 5 and Comparative Example 2 without using a binder. Therefore, a composite powder prepared using a binder appears to be more preferable for obtaining a uniform composite powder.

[Test Example 2] Evaluation of hydrophobicity of silicon-titanium dioxide composite powder

About 60 mg of the composite powder was put into 15 g of distilled water, shaken vigorously for about 30 seconds, and then stood upright to observe the cracking of the layers. If the water at the bottom is clear and the powder floats to the top, it is hydrophobic and suitable for making sunscreen. The composite powders of the present invention all showed hydrophobicity like the hydrophobic titanium dioxide powders MT-100SJ and MT-100TV.

This means that when producing composite powder using hydrophobic titanium dioxide powder of MT-100SJ or MT-100TV, hydrophobic composite powder can be obtained without going through a hydrophobization process using alkylsilane or stearic acid in the synthesis process. indicates

[Test Example 3] Particle size distribution of composite powder

The particle size distribution of the powder was measured using a laser diffraction/scattering particle size analyzer (LA 960 Laser Scattering Particle Size Analyzer, Horiba). Since the nano-sized titanium dioxide powder and the composite powder according to the present invention are hydrophobic, they were dispersed in ethanol, and 2.614 and 1.33 ethanol were applied as refractive indices of titanium dioxide rutile phase. For silicone elastomer beads, a silicone elastomer bead dispersion (SBD) containing decyl glucoside as a dispersing agent is dispersed in a small amount of water, and the refractive index of SB is 1.42 and water is 1.36. Table 1 shows.

T/T+SB CA/T G/T CA/SB
(%) μm D ₁₀ D ₅₀ D ₉₀ SB-902 5.88 9.17 15.70 MT-100SJ 0.078 0.130 0.301 Comparative Example 1 81 0 0 O 0.069 0.092 3.976 Example 1 73 0.6 5.5 0 2.63 4.18 6.00 Example 2 73 0.4 5.1 0 2.50 4.06 5.86 Example 4 61 0 5 0 4.07 7.79 14.13 Example 5 61 0 0 0.2 3.41 7.38 14.06

T: titanium dioxide (MT-100SJ), SB: silicon beads (SB 902), CA: citric acid, G: binder.

T/T+ SB CA / T G / T A / SB
(%) μm D ₁₀ D ₅₀ D ₉₀ SB-902 5.88 9.17 15.70 Example 6 60 0.85 3.6 0.6 3.73 6.95 11.83 Example 7 60 0.6 5 0 3.55 6.36 10.69

T:MT-100TV, SB:silicone bead, CA:citric acid, G:binder, A:A1120

Nano titanium dioxide powder MT-100SJ and MT-100TV are expected to have severe aggregation with particle diameters of 20 nm and 15 nm, respectively, and the instrument measurement limit is over ₃₀ nm, so a tendency can be seen. It can be seen that the D ₅₀ is about 130 nm (0,13 ㎛) and is a fine powder, and the silicone elastomer beads (SB) have a D ₅₀ of about 9 ㎛ and a D ₉₀ of about 16 ㎛, which is similar to the SEM picture. there is. However, in Examples 1 to 7 in which the additive was used, the aggregation of SB was broken, resulting in small-sized powder. Example 4 using only a binder and Example 5 in which the surface of SB was modified with citric acid showed similar particle size distributions, D ₁₀ = 3 to 4 μm and D ₅₀ = about 7 μm, and citric acid was used to disperse titanium dioxide. In the case of Examples 1 and 2 using the dispersing agent, the aggregation was well broken and the particles became small, and D ₁₀ = about 2.5 μm, D ₅₀ = about 4 μm, and D ₉₀ = about 6 μm. This is considered to be because the titanium dioxide is well dispersed into the nanoparticles, and the nanoparticles break the weak bonds of the silicon agglomerates and attach to the surface of the silicon elastomer beads to prevent aggregation from occurring even when dried.

For comparison, Comparative Example 1 without additives was measured to have D ₁₀ = 69 nm and D ₅₀ = 92 nm, and these results are almost the same as the distribution of titanium dioxide powder MT-100SJ, which indicates that titanium dioxide is a silicone elastomer. It suggests that the titanium dioxide powder and the silicone elastomer beads are not attached to the bead surface and are in a mixed state. Therefore, it was found that additives such as a dispersing agent, a binding agent, or a binder are essential for preparing the composite powder.

In addition, in Examples 6 and 7 using MT-100TV having titanium dioxide particles of 15 nm, aggregation between silicone elastomer beads was greatly broken, D ₁₀ = about 4 μm, D ₅₀ = about 7 μm, D ₉₀ = about 11 μm. It can be seen that the size of the composite powder is greatly reduced.

[Test Example 4] Evaluation of UV blocking performance

The UV blocking performance was measured at 290 to 400 nm using Solar Lights' SPF-290AS in vitro according to ISO 24443 and expressed as SPF/PA value. In the sunscreen product components of Table 3 below, only the inorganic blocker component was prepared for comparison with the complex powders developed in the present invention at a content of 15% by weight, and the content was 1.3 mg/cm on a 5 cm x 5 cm PMMA plate. It was applied and measured. In addition, nano ZnO powder, an inorganic sunscreen in the UVA region, was replaced by 5% by weight and mixed in a composition of 10 + 5, measured and compared, and shown in Table 4.

ingredient INCI designation manufacturer weight% One DC 245 cyclopentasiloxane Dow Corning 12.00 2 KF-6017 PEG-10 dimethicone Shin-Etsu 1.00 3 KF-6038 Lauryl PEG-9 Polydimethylsiloxyethyl
Dimethicone, Tocopherol Shin-Etsu 4.00 4 PARSOL MCK Ethylhexyl Methoxycinnamate DSM 7.00 5 FINSOLV TN-O C12-15 alkyl benzoate Finetex 3.00 6 DEKANEX 2006 FG Hydrogenated Polydecene Jan Dekker 2.00 7 OLIVEM 1000 Cetearyl Olivate & Sorbitan Olivate B&T 2.00 8 BEES WAX beeswax Kahl & Co. 1.50 9 SHER BUTTER Butyrospermum Parkii (Shea Butter) Karlshamns AB 0.50 10 TOCOPHEROL tocopherol Jedwards 0.10 11 BENTONE #38 Quaternium 18 Hectorite Elementis Specialties 0.50 12 TiO2 or complex powder 15 13 DI WATER water 46.58 14 EDTA 2Na Disodium EDTA Nagase 0.02 15 1,3 BG butylene glycol Daicel 2.00 16 HEXAIMA LMT 1,2-hexanediol AQP 2.00 17 NaCl sodium chloride one year old money 0.60 18 portulaca extract Portulaca Extract NEOCHEMKOREA 0.10 19 green tea extract Camellia Sinensis Leaf Extract NEOCHEMKOREA 0.10 gun 100.00

Sample T/T+SB
(%) SPF/PA
(in vitro) UA/UB λ _CRIT
(nm) inorganic blocker
/Sunscreen (%) MT-100SJ 100 58.3/40.4 0.406 365.2 15 T80 100 44.5/15.6 0.52 378.5 15 T80AS 100 58.4/20.6 0.517 377.7 15 Example 1 73 55.2/39.7 0.382 364.6 15 Example 3 61 68.1/35.6 0.437 370.6 10+5
(ST + ZnO) Example 4 61 55.5/27.8 0.403 368.8 10+5
(ST + ZnO) Example 5 61 59.3/28.3 0.432 370.2 10+5
(ST + ZnO) MT-100TV 100 79.2/43.8 0.471 371.1 15 Example 6 60 63.7/33.1 0.42 370.1 10+5
(ST + ZnO)

T: MT-100SJ or MT-100TV (titanium dioxide powder), T80 or T80AS (non-nano titanium dioxide powder, Sunjin Beauty Science); SB: silicone elastomer bead; S-T: composite powder of silicone elastomer beads and titanium dioxide

In Table 4, the sun protection factor SPF/PA of Example 1 using the composite powder of the present invention having a titanium dioxide content of 73% by weight was 55.2/39.7, corresponding to 58.3/40.4 of MT-100SJ, and nanoparticles penetrate the skin. It was shown that excellent UV blocking performance can be exhibited even when the size is several μm without controversy. This shows a superior UV blocking effect than the non-nano products T-80 and T-80AS, and in particular, shows that the UVA blocking effect is greatly superior.

Examples 3 to 6 are composite powders having a titanium dioxide content of 60% by weight or 61% by weight, and 10% by weight of titanium dioxide and 5% by weight of ZnO were used by replacing 5% by weight with nano-ZnO powder having excellent blocking ability in the UVA region. Sunscreen was prepared and measured, and SPF > 50 and PA > 28 showed excellent performance (a PA of 20 or more corresponds to PA ++++).

Claims (12)

a core made of spherical silicone elastomer beads; and
A shell made of nano-sized titanium dioxide particles and additives
and wherein the additive is at least one selected from the group consisting of a dispersing agent, a binder, and an organic-inorganic composite sol binder. The silicon-titanium dioxide for UV protection according to claim 1, wherein the dispersant is at least one selected from the group consisting of citric acid, malic acid, maleic acid, fumaric acid, succinic acid, acetic acid, formic acid, butanoic acid, hydrochloric acid and nitric acid. composite powder. The silicon-titanium dioxide composite powder for blocking ultraviolet rays according to claim 1, wherein the dispersant is included in an amount of 0.3 to 3% by weight based on titanium dioxide. The method of claim 1, wherein the binder is at least one selected from the group consisting of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane and 3-(2-aminoethylaminopropyltriethoxysilane) Silicon-titanium dioxide composite powder for UV protection. The silicon-titanium dioxide composite powder for blocking ultraviolet rays according to claim 1, wherein the binder is included in an amount of 0.05 to 3% by weight based on titanium dioxide. The method of claim 1, wherein the organic-inorganic composite sol binder
(a) forming an alumina sol by dispersing boehmite powder in distilled water and then adding an acid and stirring; and
(b) mixing and heating the formed alumina sol and epoxysilane
Silicon-titanium dioxide composite powder for UV protection, characterized in that produced by. The silicon-titanium dioxide composite powder for blocking ultraviolet rays according to claim 1, wherein the binder is included in an amount of 2 to 15% by weight based on titanium dioxide. The silicon-titanium dioxide composite powder for blocking ultraviolet rays according to claim 1, wherein the silicon elastomer beads are synthesized by polymerization of vinyl silicon and hydrogen silicon. The silicon-titanium dioxide composite powder for blocking ultraviolet rays according to claim 1, wherein the content of the titanium dioxide particles in the composite powder is 40 to 80% by weight based on the total weight of the composite powder. (1) preparing a titanium dioxide slurry by dispersing nano-sized titanium dioxide powder in alcohol in an amount of 10 to 40% by weight based on the total weight of the slurry;
(2) 5 to 30 silicone elastomer beads based on the total weight of the dispersion preparing a silicone aqueous dispersion in weight percent;
(3) mixing the slurry of (1) and the dispersion of (2) to form a precipitate;
(4) separating the precipitate of (3) and drying it at high temperature to produce a composite powder; and
(5) pulverizing the composite powder of (4) by dry milling to prepare micron-sized powder;
Including,
Mixing additives in at least one of step (1), step (2) or step (3),
The additive is a dispersing agent, a binder and organic-inorganic composite sol binders. 11. The method of claim 10, wherein the alcohol used in step (1) is at least one selected from the group consisting of ethanol, isopropanol and butanol. A cosmetic composition for sunscreen comprising the silicon-titanium dioxide composite powder for sunscreen according to any one of claims 1 to 9.

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